Cognitive Brain Functions
The
human brain is divided in many different areas that perform vital activities
crucial for the functioning of the human body. According to Dr. J. A. Stevens Williams, “at
the most general level, human cognitive processing occurs in the cortex, the
outer layer of the brain composed of folds (gyri) and crevices (sulci) of
tissue” (2010). Understanding the detailed cortical map has been extremely
important for the development of the study of cognitive functions, because it
allowed scientists to learn that specific regions of tissue are responsible for
different cognitive processes. For instance, there are regions in charge of
decision making, language skills, visual processing and so on. Great advances
in cognitive neuroscience over the past couple of decades, paired with
technological innovations for brain imagining, have allowed scientists to
identify affected areas of the brain and how the human behavior can change if a
specific part of the brain is affected.
Human
cognitive functions originate in a part of the brain called cerebrum, also
known as the cerebral cortex. This area is composed by four different lobes:
the frontal lobe, the temporal lobe, the occipital lobe, and the parietal lobe.
Each one of these areas is responsible for specific cognitive tasks, and some
of these tasks such as reading, speaking, or leaning require multiple areas of
the cerebrum to work together (Jeanty, 2013). For cognitive functions to
happen, it is necessary for neurotransmitter processes to coordinate signals
between different parts of the brain. These neurotransmitters, which are
chemicals produced by nerve cells and released when a nerve cell is stimulated,
travel between the right and the left side of the brain, creating a
communication and a transmission of information (Jeanty, 2013).
Brain
injuries can have a great impact on the lives of those who suffered an accident
or went through a degenerative disease. Having specific parts of the brain
affected can prevent it from performing vital functions and consequently impacting
the way the victim behaves in different situations. A very well know example of
a brain injured that had an irreversible impact on the victim is the case of
Phineas Gage. Phineas P. Gage was an American railroad construction man, and is
often referred to as one of the most notorious neuroscience patients. On
September 13, 1848, Gage, who was twenty five years old at the time, was
working in a railroad near Cavendish, Vermont. While attempting to pack
explosive powder into a hole, the powder detonated and sent the rod, that was
43 inches long and had 1.25 inches in diameter, flying upward, penetrating
Gage’s left cheek, going through his brain, exiting his skull and landing
eighty feet away. Not only Phineas Gage was still alive after the accident, he
was able to talk to the doctors and tell them what had happened. His recovery
was surprisingly fast, and one month after the accident he was already leaving
his house and walking on the street. Dr. John Marty Harlow, who was in charge
of the case, noted that his patient knew very clearly how much time had passed
since the accident and remembered details about that day very vividly, but he
had a lot of difficulty with numbers, distances and amounts (Cherry, 2013).
In
the months that followed the accident, Gage recovered fairly well. He was in
good shape and had overall a good physical health. However, reports show that
his personality changed drastically. Before the accident, he was known as a
pleasant, hard-working man. Apparently after the accident he became aggressive
and irresponsible. Although there are not a lot of evidence to support the
changes in his personality, most of his friends attested that if nothing else,
he lost all social inhibition, which led to inappropriate behaviors. Because of
his curious story, Phineas Gage had a great influence on neurology. “The
specific changes observed in his behavior pointed to emerging theories about
the localization of brain function, or the idea that certain functions are
associated with specific areas of the brain. Today, scientists better
understand the role that the frontal cortex has to play in important higher
order functions such as reasoning, language, and social cognition. In those
years, while neurology was in its infancy, Gage's extraordinary story served as
one of the first sources of evidence that the frontal lobe was involved in
personality” (Cherry, 2013).
References
Cherry,
K. (2013). Phineas Gage. Retrieved from
http://psychology.about.com/od/historyofpsychology/a/phineas-gage.htm
Jeanty,
J. (2013). Cognitive brain functions. Retrieved from
http://www.ehow.com/about_5312779_cognitive-brain-functions.html
Williams, J. A.
S. (2013). Brain cognitive functions . Retrieved from
http://www.livestrong.com/article/94082-brain-cognitive-functions/
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